1. Field of the Invention
The present invention relates to an automotive air bag device that provides greater projection of a main bag unit using an inexpensive structure.
2. Description of the Related Art
Certain vehicles, such as automobiles, are equipped with conventional air bag devices serving as emergency safety measures. Conventional air bag devices contain a main bag unit stored in a folded state within a housing disposed inside the vehicle""s instrument panel. Upon an impact at or greater than a predetermined value, the main bag unit expands and projects. This expansion is driven by pressurized gas. As a result, conventional air bag devices support and protect occupants positioned at fixed distances from the air bag device.
Referring to FIG. 15, a conventional two-piece air bag device includes a main bag unit, shown generally at 15xe2x80x2, formed from a pair of base fabric sections 1, 2. A seam line 3 affixes base fabric sections 1, 2 together along a perimeter. A first side of main bag unit 15xe2x80x2 includes a gas entry opening 6 for receiving gas pressurizing main bag unit 15xe2x80x2. The first side of main bag unit 15xe2x80x2 also includes a pair of vent holes 7,7, formed for adjusting the pressure inside main bag unit 15xe2x80x2. Base fabric sections 1, 2 are conventionally affixed together by sewing along seam line 3.
Upon inflation of main bag unit 15xe2x80x2, a volume contained between base fabric sections 1,2 increases causing main bag unit 15xe2x80x2 to project away from an instrument panel (not shown) toward a desired contact position (not shown). The shape of base fabric sections 1,2 determines both the final inflated form of main bag unit 15xe2x80x2 and the amount of protection of main bag unit 15xe2x80x2 toward the desired contact position (not shown). When a manufacturer desires to change either the final inflated form or the amount of projection of conventional main bag unit 15xe2x80x2 the manufacturer must change the shape and size of base fabric sections 1,2.
Referring to FIG. 16, a conventional three-piece air bag device includes a main bag unit, shown generally at 15xe2x80x3, formed from a pair of side fabric sections 4, 4 and a band-shaped base fabric section 5. Side fabric sections 4, 4 are affixed to base fabric section 5 along perimeter sections by two seam lines (not shown). A gas entry opening 6, for receiving pressurizing gas into conventional main bag unit 15xe2x80x3, is formed by side fabric sections 4, 4 and base fabric section 5 affixed together by seam lines (not shown). A pair of vent holes, one shown at 7, is included in side fabric sections 4,4 for adjusting the pressure inside main bag unit 15xe2x80x3. Conventionally, side fabric sections 4, 4 are affixed to base fabric section 5 by sewing.
Upon inflation of main bag unit 15xe2x80x3, volume contained between side fabric sections 4, 4 and base fabric section 5, increases causing main bag unit 15xe2x80x3 to project away from an instrument panel (not shown) toward a desired contact position (not shown). Conventionally, the shape of side fabric sections 4, 4 and base fabric section 5 determines both the final inflated form of main bag unit 15xe2x80x3 and the amount of projection toward the desired contact position (not shown).
Where a manufacturer desires to change either the final inflated form or the projection amount of conventional main bag unit 15xe2x80x3 the manufacturer must change the shape or size of side fabric sections 4, 4 and base fabric section 5.
Conventional three-piece main bag unit 15xe2x80x3 provides greater projection toward the desired contact position(not shown) than conventional two-piece main bag unit 15xe2x80x2, but requires more fabric and greater labor thus adversely affecting material costs and labor costs.
It is an object of the present invention to minimize the problems described above and to provide an automotive air bag device that can increase the projection distance of a main bag unit.
It is an object of the present invention to provide an automotive air bag device that can increase the projection of a main bag unit using an inexpensive structure.
The present invention relates to an air bag unit including a restrictive element, affixed within the air bag unit which restricts lateral expansion of the air bag unit. The lateral restriction increases longitudinal expansion toward an occupant position.
According to an embodiment of the present invention there is provided, an air bag comprising: a belt in an interior of the air bag, the air bag being of a type which expands in an expansion direction into a space in a vehicle, the belt limiting expansion of the air bag in a limiting direction, and the limiting direction being at an angle to the expansion direction, whereby expansion of the air bag in the expansion direction is increased.
According to another embodiment of the present invention there is provided, an air bag device comprising: an air bag unit, the air bag unit includes at least a first and a second base piece, the base pieces affixed together along a continuous seam element, a first and a second lateral position on the seam element established relative to an optimal external occupant position, the lateral positions separated by a first distance, means for restricting fixed between the lateral positions, the means has a restrictive length, the restrictive length being less than the first distance, and the restrictive means provides reduction in the first distance thereby increasing longitudinal expansion of the air bag unit into the external occupant position.
According to another embodiment of the present invention there is provided, an air bag device wherein: the restricting means is a belt, the belt having a first and second end and a first and second intermediate position, the first and the second ends affixed together, the first intermediate position on the belt affixed to the first lateral position, and the second intermediate position is affixed to the second lateral position.
According to another embodiment of the present invention there is provided, an air bag device wherein: the belt includes an intermediate section between the first and second intermediate positions, and the intermediate section overlapped and sewn thereby adjusting the restricting length.
According to another embodiment of the present invention there is provided, an air bag device further comprising: means for minimizing expansion failure along the perimeter seam element, and the minimizing means absorbs expansion force thereby preventing the perimeter seam element from failing when the air bag expands.
According to another embodiment of the present invention there is provided, an air bag device wherein: the minimizing means includes a first and a second margin extending from the base pieces, the margins extend away from the corresponding lateral positions, the restrictive means affixed between the first and the second margins along a pair of seams distinct from the continuous seam element, and the margins preferentially failing under expansion pressure thereby preventing the perimeter seam element from failing.
According to another embodiment of the present invention there is provided, an air bag device wherein: the minimizing means includes a first and a second weak section, the weak sections formed between the seam element and each the corresponding margin, and the weak sections preferentially failing under expansion pressure there preventing the perimeter seam element from failing.
According to another embodiment of the present invention there is provided, an air bag device, further comprising: a third base piece, the third base pieces fixed in two continuous seam elements to the first and second base pieces, and the third base piece provides further longitudinal expansion of the air bag unit relative to the occupant position.
According to another embodiment of the present invention there is an automotive air bag device equipped with a main bag unit, the main bag unit comprising: a first and a second base fabric, each of the first and second base fabrics has substantially the same shape, each of the first and second base fabrics fixed together along an outer perimeter by a seam line, the outer perimeter having a first and a second lateral side, the lateral sides positioned relative to an occupant position, the lateral sides separated by a distance, means for restricting expansion of the main bag unit during inflation, and the restrictive means provides localized reduction of the distance between the lateral sides thereby increasing projection of the main bag unit towards the occupant position.
According to another embodiment of the present invention there is a main bag unit, wherein: the width restricting means is a belt having a first and a second end, the belt being sewn to the base fabrics along each lateral side, and a pair of positions intermediate the ends sewn together thereby increasing projection of the main bag unit towards the occupant.
According to another embodiment of the present invention there is a main bag unit, wherein: each lateral side is positioned relative to an upper body portion of the occupant position.
According to another embodiment of the present invention there is a main bag unit, further comprising: a pair of margins extending from the base fabrics away from the outer perimeter, and the width restricting means affixed along each margin at a correspond lateral seam line adjacent to the lateral sides.
According to another embodiment of the present invention there is a main bag unit, further comprising: a first and a second weak section, each weak section positioned between each the corresponding margin and the seam line.
According to another embodiment of the present invention there is a main bag unit, wherein: the restrictive means overlapped at an intermediate section, and an intermediate seam line fixed across said intermediate section thereby reducing said distance between said lateral sides.
The above, and other objects, features and advantages of the present invention will become apparent from the following description read in conjunction with the accompanying drawings, in which like reference numerals designate the same elements.